Anoxygenic photosynthesis is characteristic of

$A$ block of mass $2 ~kg$ is initially at rest on a horizontal frictionless surface. $A$ horizontal force $\overrightarrow{F} = (9 - x^2) \hat{i} ~N$ acts on it,starting from $x = 0$. The maximum kinetic energy of the block between $x = 0$ and $x = 3 ~m$ in joules is:

For a Poisson variate $X$,if $P(X=2)=3 P(X=3)$,then the mean of $X$ is :

Let $R$ and $S$ be two relations on a set $A$. Then which of the following statements is true?

$A$ circular coil having $N$ turns is made from a wire of length $L$ meters. If a current of $I$ amperes is passed through it and placed in a magnetic field of $B$ tesla,the maximum torque on it is

Among the following compounds,which one is not responsible for the depletion of the ozone layer?